3.6

1 files changed, 66 insertions, 0 deletions

diff --git a/3/6.c b/3/6.c
new file mode 100644
index 0000000..bb3636f
--- /dev/null
+++ b/3/6.c
@@ -0,0 +1,66 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define MAXLEN 1000
+
+/* converts n to s with width w */
+void itoa(int n, char s[], int w);
+
+int main(int argc, char *argv[]) {
+  int i, c, n, w;
+  char s[MAXLEN];
+
+  printf("Number to convert to string: ");
+  for (i = 0; i < MAXLEN - 1 && (c = getchar()) != '\n' && c != EOF; i++)
+    s[i] = c;
+  s[i] = 0;
+  n = atoi(s);
+
+  printf("Width: ");
+  for (i = 0; i < MAXLEN - 1 && (c = getchar()) != '\n' && c != EOF; i++)
+    s[i] = c;
+  s[i] = 0;
+  w = atoi(s);
+
+  itoa(n, s, w);
+  printf("%d as string of width %d: %s\n", n, w, s);
+
+  return 0;
+}
+
+void reverse(char s[]) {
+  int c, i, j;
+
+  for (i = 0, j = strlen(s) - 1; i < j; i++, j--) {
+    c = s[i];
+    s[i] = s[j];
+    s[j] = c;
+  }
+}
+
+void itoa(int n, char s[], int w) {
+  int i;
+
+  i = 0;
+
+  if (n >= 0) {
+    do {
+      s[i++] = n % 10 + '0';
+    } while ((n /= 10) > 0);
+  } else {
+    do {
+      s[i++] = -(n % 10) + '0';
+    } while ((n /= 10) <= -1);
+  }
+
+  if (n < 0)
+    s[i++] = '-';
+
+  while (i < MAXLEN - 1 && i < w)
+    s[i++] = ' ';
+
+  s[i] = 0;
+
+  reverse(s);
+}
\ No newline at end of file